Suction drum device and air joint

ABSTRACT

A suction drum device has a rotary suction drum that has air holes formed around its peripheral surface. A surface of a stationary sucking blowing block is tightly pressed on a side surface of the suction drum, so the side surface of the suction drum slides on the tight-pressed surface of the sucking blowing block. The side surface of the suction drum is formed with openings, each of which leads to a group of the vent holes. A sucking hole and a blowing hole are formed in the tight-pressed surface of the sucking blowing block, which are connected to a vacuum pump and an air blower respectively. As the suction drum rotates, a number of openings are connected to the sucking hole, so the air is sucked through the vent holes that lead to these openings. When one of the openings is connected to the blowing hole, the air is blown out through those vent holes which lead to the one opening. The tight-pressed surface of the sucking blowing block further has recesses and an endless groove surrounding the sucking hole for pooling lubricant. Endless grooves are also formed around the respective openings of the sliding surface of the suction drum, for catching the lubricant.

FIELD OF THE INVENTION

The present invention relates to an air joint that consists of a stationary member having vent holes formed through at least one of its surfaces, and a movable member having vent holes formed through a surface that slides on the surface with the vent holes of the stationary body, wherein the vent holes of the movable member are connected to the vent holes of the stationary member so that the air flows from the stationary member to the movable member or vise versa via the vent holes. More particularly, the present invention relates to a suction drum device that is provided with a suction drum that rotates to convey a belt-like material while sucking and holding the belt-like material on its peripheral surface.

BACKGROUND ARTS

Suction drum devices have been widely used, which uses a suction drum as a conveyer for conveying a belt-like material such as a magnetic tape, paper, and metal foil. As well known in the art, the suction drum is a rotary drum that rotates to convey a belt-like material while holding it on its peripheral surface by sucking the air through vent holes that are formed through the peripheral surface. As such suction drums, so-called double-drum type suction drums are well known. As disclosed for example in page 1 of Japanese Laid-open Patent Application No. Hei 2-158555 and page 2 of Japanese Laid-open Patent Application No. Hei 8-175718, the double-drum type suction drum is constituted of an external rotary barrel that is hollow inside and has vent holes through its peripheral surface, an internal barrel that is placed inside the external barrel and forms a hermitic vacuum room between the external barrel, and an air duct provided in the internal barrel to connect a sucking device and the vacuum room.

Since the air is sucked through the vent holes only while the vent holes are connected to the sucking device by way of the vacuum room as the vent holes move with the rotation of the external barrel, the double-drum type suction drum can stop sucking the air through those vent holes which move in a range where the peripheral surface of the drum need not to hold the belt-like material thereon. Therefore, material even with a cheap low power vacuum pump, it is possible to achieve a sufficiently high sucking pressure enough to prevent slippage of the sheet. However, because a gap between the external barrel and the internal barrel is sealed by use of a sealing material to close the vacuum room hermetically, the vent holes can be clogged up with powders of the sealing material as generated by friction and collected between the external barrel and the internal barrel.

To solve this problem, a suction drum has been suggested for example in Japanese Laid-open Patent Application No. 2004-26348, wherein a plurality of openings are formed through a side surface of the suction drum, and the openings lead each individually to a constant number of vent holes which are formed through a peripheral surface of the suction drum. That is, the vent holes are connected to the openings through air ducts that are formed radially inside the suction drum. On the side surface of the suction drum is tightly pressed a sucking block that is formed with a sucking hole. The sucking hole is connected to a sucking device, and has such a shape that it is connected to the openings only while the vent holes assigned to these openings exit in a rotational range where the suction drum is expected to suck the belt-like material on its peripheral surface. Accordingly, the air is sucked merely through those vent holes which need to suck the belt-like material in accordance with the rotational phase of the suction drum. Therefore, like the double-drum type suction drum, a high sucking pressure is achieved even if the sucking device has a small sucking power.

Meanwhile, if the suction drum rotates at a high speed to convey the belt-like material at a correspondingly high speed, there is a possibility that the belt-like material cannot remove of f the drum peripheral surface at a designed position, because the belt-like material is sucked on the peripheral surface. If the belt-like material is cut at a downstream position near behind the suction drum, the tension to pull the belt-like material in the conveying direction can be so small that it becomes more difficult to remove the belt-like material off the peripheral surface.

To solve this problem, the above mentioned sucking block usually has a blowing hole beside the sucking hole. The blowing hole is connected to a blowing device, and is located to be connected to one of the openings that leads to those vent holes which come to the designated separating position for the belt-like material, as the suction drum rotates. Accordingly, when the vent holes come to the separating position, the air is not sucked through these vent holes but, on the contrary, the air is blown out through these vent holes. So the sheet is forcedly separated from the drum peripheral surface at the separating position. As a result, the belt-like material is sucked on and then peeled off the drum peripheral surface without fail, so it becomes possible to convey the belt-like material properly.

The suction drum disclosed in Japanese Laid-open Patent Application No. 2004-26348 rotates while a sucking blowing block is tightly pressed on a side surface of the suction drum. For the purpose of reducing friction between the side surface of the suction drum and the tight-pressed surface of the sucking blowing block, these surfaces are lubricated. If the amount of lubrication is small, the lubricant will run out soon. The lack of lubricant will induce wearing of the side surface of the suction drum and the tight-pressed surface of the sucking blowing block rapidly.

Applying an increased amount of lubricant will elongate the time running out of the lubricant. However, since the side surface of the suction drum and the tight-pressed surface of the sucking blowing block are flat, the increased amount of lubricant is more likely to collect in the openings and the sucking hole. As a result, the lubricant may leak from the openings into the air duct as the air is sent from the air blower, or leak from the sucking hole as the air is sucked by the sucking device. The leakage causes running out of the lubricant in a shorter time, or the lubricant leaked in the air duct may be ejected out of the vent holes with the blowing air, and smear the belt-like material.

The same problem applies to any kind of air joint that consists of a stationary member having vent holes formed through a surface, and a movable member having holes formed through a surface that is tightly pressed and slides on the surface with the vent holes of the stationary body, wherein these surfaces are lubricated to reduce the friction.

SUMMARY OF THE INVENTION

In view of the foregoing, a primary object of the present invention is to provide an air joint and a suction drum device, which prevent the leakage of the lubricant even with a sufficient amount of lubricant.

To achieve the above and other objects, according to the present invention, an air joint comprising a stationary member having vent holes formed through at least one of its surfaces; a movable member having vent holes formed through a sliding surface that slides on the surface with the vent holes of the stationary body, the vent holes of the movable member being connected to the vent holes of the stationary member so the air flows from the movable member to the stationary member or vise versa via the vent holes; and grooves formed around at least some of the vent holes.

Because the grooves catch redundant lubricant, it becomes possible to lubricate the sliding surface sufficiently enough to prevent the frictional wearing for a long time.

It is preferable to set back boundary portions between the vent holes and the grooves from the sliding surface. Thereby the leakage of the lubricant is more efficiently suppressed.

According to a preferred embodiment, at least a groove is formed in an outer peripheral surface of the boundary portion, the groove extending in a circumferential direction of the vent hole. The groove formed in the outer peripheral surface of the boundary portion serves as an oil trapping groove, so the leakage of the lubricant is still more efficiently suppressed.

A suction drum device of the present invention, comprises a negative pressure source; a stationary member having a suction hole formed through a surface, the suction hole leading to the negative pressure source; a rotary drum having air holes formed through an outer peripheral surface, and openings formed through a side surface of the rotary drum, the openings leading to the air holes, the side surface sliding on the surface of the stationary member to connect the openings in turn to the suction hole as the rotary drum rotates, thereby sucking the air through some of the air holes to hold a belt-like material on the outer peripheral surface; and grooves formed around the suction hole of the stationary member and/or around at least some of the openings of the rotary drum.

It is preferable to set back a boundary portion between the suction hole and the groove or boundary portions between the openings and the grooves from the sliding surface.

According to a preferred embodiment, at least a groove is formed in an outer peripheral surface of the boundary portion, the groove extending in a circumferential direction of the suction hole or the openings.

According to a preferred embodiment, the air holes are divided into groups of a constant number according to their positions on the outer peripheral surface of the rotary drum, and the openings lead each individually to one group of the air holes, and are arranged at regular intervals in a circle around a rotary center of the rotary drum.

The stationary member may further has a blowing hole connected to a positive pressure source, the blowing hole being formed through the surface having the suction hole, wherein the suction hole is connected to a constant number of successive ones of the openings so as to suck the air through those groups of the air holes which lead to the successive openings, whereas the blowing hole is connected to at least one of the openings so as to blow out the air through the air holes which lead to the at least one opening.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and advantages will be more apparent from the following detailed description of the preferred embodiments when read in connection with the accompanied drawings, wherein like reference numerals designate like or corresponding parts throughout the several views, and wherein:

FIG. 1 is a schematic diagram illustrating a photo film roll manufacturing line that is provided with a suction drum device of the present invention;

FIG. 2 is a schematic diagram illustrating a film supplier disposed at an upstream position of a film supply line of the photo film roll manufacturing line;

FIG. 3 is a side view of the suction drum device according to an embodiment of the present invention;

FIG. 4 is a sectional view of a drum body of a suction drum of the suction drum device, taken along a line IV-IV of FIG. 3;

FIG. 5 is a front view of a flange of the suction drum;

FIG. 6 is a front view of a sucking blowing block of the suction drum device, seen from a surface that is tight-pressed onto the suction drum and has a suction hole and a blowing hole formed therein;

FIG. 7 is an explanatory diagram illustrating shapes and positions of the suction hole and the blowing hole in relation to the openings formed in the flange of the suction drum;

FIG. 8 is an enlarged view of the opening of the flange;

FIG. 9 is a sectional view of the opening of the flange; and

FIG. 10 is a sectional view of the opening of the flange, having a simplified structure according to another embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a photo film roll manufacturing line 10 for manufacturing ISO 120-type photo film rolls. The photo film roll manufacturing line 10 is mainly constituted of a film supply line 14 for supplying photo filmstrips 13, a backing paper supply line 17 for supplying light-tight backing paper 32, and a spool supply line 20 that is positioned at a junction of the film supply line 14 and the backing paper supply line 17, to supply spools 19 and wind up the filmstrip 13 and the backing paper 32 around the spool 19.

The film supply line 14 is constituted of a film supplier 22, a film cutter 23 and a bonding tape applier 24, which are arranged in this order from upstream of the line 14, and conveyer rollers 25 disposed between these members. The film supplier 22 is provided with a suction drum device of the present invention. As set forth in detail later, the film supplier 22 is loaded with first and second film supply rolls 27 a and 27 b, each of which is formed by winding a long web of photo film 26 into a roll (see FIG. 2). The film supplier 22 withdraws the photo film web 26 from these film rolls 27 a and 27 b a predetermined length at a time, prints film data, including film size, film speed and film type, on side margins of the photo film web 26 and, thereafter, feeds the photo film web 26 to the film cutter 23.

The film cutter 23 cuts the photo film web 26 into the predetermined length to provide the photo filmstrip 13. The photo filmstrip 13 is fed to the bonding tape applier 24. Although it is not shown in the drawings, the adhesive tape applier 24 is loaded with a roll of release paper or exfoliate paper having adhesive tapes put thereon. The adhesive tape applier 24 withdraws the release paper from the roll, peals the adhesive tape off the release paper, and puts the adhesive tape on a trailing end of each photo filmstrip 13. Thereafter, the photo filmstrip 13 is conveyed to the spool supply line 20.

The backing paper supply line 17 is constituted of a backing paper supplier 29, a sealing tape applier 30 and a backing paper cutter 31, which are arranged in this order from upstream of the line 17, and conveyer rolls 33 disposed between these members to convey the backing paper 32 along the line 17. Although it is not shown in the drawings, the backing paper supplier 29 is loaded with a roll of long web of light-tight backing paper 32. The backing paper supplier 29 withdraws the backing paper 32 from the roll a predetermined length at a time, trims the backing paper, provides the backing paper with perforations for use in winding it around the spool 19 and, thereafter, feeds it to the sealing tape applier 30.

Although it is not shown in the drawings, the sealing tape applier 30 is loaded with a roll of sealing tape ribbon. The sealing tape applier 30 withdraws the sealing tape ribbon from the roll, cuts the ribbon into a constant length, and bonds the sealing tape on a given portion of each backing paper 32 by heat-pressing an adhesive surface of the sealing tape on the backing paper 32, using a not-shown heat sealer. Thereafter, the backing paper 32 is conveyed to the backing paper cutter 31.

The backing paper cutter 31 is disposed as close to the spool supply line 20 as possible, in order to shorten the takt time of the manufacturing line 10. The backing paper cutter 31 cuts the backing paper 32 into a backing paper strip of a predetermined length, each time the backing paper 32 is wound up by the predetermined length onto the spool 19. A pair of back tension rollers 34 are disposed before the backing paper cutter 31, to apply a backward tension to the backing paper 32 so as to prevent fluctuation and meandering of the backing paper 32 as it is wound together with the photo filmstrip 13 around the spool 19.

The spool supply line 20 is constituted of a spool turret 35 having a round rotary disc mounted on a shaft, a spool supplier 36 placed at a peripheral position of the spool turret 35 to supply the spool turret 35 with the spools 19, a spool positioning machine 37 for positioning the spools 19 on the spool turret 35 with respect to a not-shown winding slit that is formed through each spool 19, a winding machine 38 disposed in a dark room and used for winding the photo filmstrip 13 and the backing paper strip around the spool 19, a folding machine 39 for folding a trailing end of the backing paper strip inward after the backing paper strip is wound around the spool 19, a seal wrapping machine 40 for wrapping a not-shown sealing tape around the rolled backing paper strip, an inspector 43 for inspecting each of manufactured photo film rolls 42 as to whether it has a proper diameter or not, and an accumulating conveyer 44 for conveying the complete photo film rolls 42, after they pass the inspection, to the following processing machines such as a packaging machine.

The spool turret 35 is driven by a not-shown motor to turn intermittently by an angle of 45 degrees in a clockwise direction in FIG. 1. The spool turret 42 has spool holders 46 which are located at regular intervals around the rotary center, to hold the spools 19. The spool holders 46 are connected to a not-shown motor that rotates the spools 19 in a winding direction. A touch roller device 47 for pressing the photo filmstrip 13 and the backing paper strip onto a shaft of the spool 19 is disposed in the vicinity of each spool holder 46.

The spool holders 46 stop turn by turn at predetermined positions during each intermission of the spool turret 35, and these predetermined positions include first to seventh stations ST1, ST2, ST3, ST4, ST5, ST6 and ST7, where the spool supplier 36, the spool positioning machine 37, the winding machine 38, the backing paper folding machine 39, the seal wrapping machine 40, the inspector 43 and the accumulating conveyer 44 are respectively disposed.

As shown in FIG. 2, the film supplier 22 is mainly constituted of a couple of carriers 48 a and 48 b carrying the film supply rolls 27 a and 27 b to rotate thereon, dancer roller mechanisms 49 a and 49 b, to which the photo film webs 26 are fed out from the film supply rolls 27 a and 27 b, a roll switching device 50 for feeding either of the photo film webs 26 to a downstream side, and a film splicer 51 disposed at a downstream position of the roll switching device 50, for splicing a leading end of a following one of the two photo film webs 26 to a trailing end of a foregoing one of the two photo film webs 26. The film supplier 22 also has a suction drum device 52 for feeding the photo film web 26 to the film cutter 23, and a number of pass rollers 53 disposed between these devices. The suction drum device 52 is configured according to an embodiment of the present invention, as will be described in detail later.

The dancer roller devices 49 a and 49 b are for keeping the photo film web 26 in a tensed condition by applying a certain weight onto the photo film web 26. Each of the dancer roller devices 49 a and 49 b is mainly constituted of a dancer roller 55 for applying the weight onto the photo film web 26, an arm 56 for holding the dancer roller 55 at its one end, an arm holder 57 for holding the arm 56 pivotally at the other end of the arm 56. Although it is not shown in the drawings, the dancer roller devices 49 a and 49 b are each provided with a position detector for detecting the position of the dancer roller 55. The photo film web 26 is prevented from loosening by adjusting the speed of feeding the photo film web 26 out of the film supply roll 27 a or 27 b so as to keep the dancer roller 55 in a predetermined positional range while referring to the detection results of the position detector.

The roll switching device 50 is constituted of a sector-shaped switching plate 60 that is pivotally held by a holder base 59, first and second film end holders 61 a and 61 b for clamping respective leading ends of the photo film webs 26 as fed out from the film supply rolls 27 a and 27 b, pass rollers 53 around which the photo film webs 26 are turned, and conveyer roller pairs for conveying the leading ends of the photo film webs 26 toward the film splicer 51, which are not shown but provided in the film end holders 61 a and 61 b. The switching plate 60 is driven by a not-shown motor to swing between two positions at which either of the first and second film end holders 61 a and 61 b is opposed to the film splicer 51. For example, after the photo film web 26 is entirely fed out from the first film supply roll 27 a through the first film nipper 61 a, the switching plate 60 is swung to oppose the second film nipper 61 b to the film splicer 51. Then the leading end of the photo film web 26 is fed out from the second film nipper toward the film splicer 51.

Although it is not shown in the drawings, the film splicer 51 is constituted of a cutter for cutting the photo film web 26 at its trailing end after the photo film web 26 is entirely fed out from the film supply roll 27 a or 27 b, and a splicer for splicing the trailing end of the foregoing photo film web 26 to the leading end of the following photo film web 26 that is sent out from the roll switching device 50. The splicer can be a microwave splicer or an adhesive tap applier, or any type of splicer insofar as it can splice the photo film webs 26 to one another. The spliced photo film web 26 is fed toward the film cutter 23 by use of the suction drum device 52.

Now the suction drum device 52 will be described with reference to FIGS. 3 to 6. FIG. 3 shows a side view of the suction drum device 52. The suction drum device 52 is mainly constituted of a suction drum 65 affixed to one end of a rotary shaft 64, a conveyer motor 66 coupled to the other end of the rotary shaft 64 to rotate the rotary shaft 64, a sucking blowing block 70 tightly pressed onto a right side of the suction drum 65 in FIG. 3, a motor mounting member 71 for mounting the conveyer motor 66, a bearing member 74 for pivotally supporting the rotary shaft 64 through a bearing 73, and a base 75 supporting the motor mounting member 71 and the bearing member 74 to stand thereon. The suction drum 65 has a large number of air holes 63 formed through its peripheral surface. As the suction drum 65 rotates while sucking the photo film web 26 onto the peripheral surface, the photo film web 26 is conveyed through the suction drum 65. The sucking blowing block 70 is connected to a vacuum pump or sucking device 68 as a negative pressure source, and an air blower or a blowing device 69 as a positive pressure source.

The suction drum 65 is preferably a rotary drum made of an iron material called SS400 that is processed through Tufftride treatment. The suction drum 65 consists of a cylindrical drum body 77 having the air holes 63 formed through its peripheral surface, and round flanges 78 a and 78 b which are provided on the right and left sides of the drum body 77 in FIG. 3, and has a larger diameter and the drum body 77. The suction drum 65 is a rotary drum that rotates with the rotary shaft 64 as the rotary shaft 64 is rotated by the conveyer motor 66.

The air holes 63 are arranged in two lines along a circumferential direction or rotational direction of the suction drum 65, at a constant interval in each line. As shown in a section in FIG. 4, the air holes 63 are formed from the peripheral surface of the drum body 77 to internal air ducts 80. In FIG. 4, the flange 78 b is omitted for clarity sake. The air ducts 80 extend in parallel to an axial direction of the rotary shaft 64 as well as radially toward the peripheral surface, and are arranged radially at constant intervals about the rotary shaft 64. According to the present embodiment, every air duct 80 is connected to a constant number of air holes 63. Accordingly, when the air is sucked through one of the air ducts 80, the air is sucked simultaneously through all of those air holes 63 connected to this air duct 80.

The flanges 78 a and 78 b limit the lateral position of the photo film web 26 as it is sucked and conveyed on the peripheral surface of the suction drum 65. The flanges 78 a and 78 b are configured identically to each other. As shown with respect to the flange 78 a in FIG. 5, the flanges 78 a and 78 b are affixed to the opposite sides of the drum body 77 by screws 82 that are screwed into screw holes 81 of the drum body 77, so that the flanges 78 a and 78 b tightly close the air ducts 80 which are otherwise exposed on the opposite sides of the drum body 77. According to the present embodiment, the flange 78 a has round openings 83 formed through its external surface, which are arranged in a circle that is coaxial to the rotary shaft 64. The openings 83 are spaced constantly from each other so as to be connected to the air ducts 80 in one to one relationship, so that each opening 83 is connected to the constant number of air holes 63 via the individual air duct 80. Since the openings 83 are arranged at the same radius from the rotary axis of the rotary shaft 64, they move along the same track with the rotation of the suction drum 65.

The sucking blowing block 70 is a block made of an iron material called SS400 that is processed through Tufftride treatment, like the suction drum 65, and has a substantially cylindrical shape. As shown in FIGS. 2 and 6, the sucking blowing block 70 is shaped to be fit on the rotary shaft 64 through a bearing 85. A guide mechanism 86 consisting of a suspension and a bushing, which are mounted to the bearing member 74, holds the sucking blowing block 70 to be able to slide along the rotary shaft 64. Between the sucking blowing block 70 and the bearing member 74, a compressed coiled spring 87 is force-fitted on the rotary shaft 64, so that the sucking blowing block 70 is pressed tightly on one side of the suction drum 65, that is, on the flange 78 a. Because the guide mechanism 86 fixes the rotational position of the sucking blowing block 70, the sucking blowing block 70 will not rotate along with the suction drum 65.

As described above, the sucking blowing block 70 is connected to the vacuum pump 68 through a sucking pipe 89, as well as to the air blower 69 through a blowing pipe 90. The sucking pipe 89 and the blowing pipe 90 go through inside the sucking blowing block 70, and are connected respectively to a suction hole 91 and a blowing hole 92, which are formed in a surface of the sucking blowing block 70 that is tightly pressed onto a side surface of the suction drum 65, i.e. the external surface of the flange 78 a, as shown in FIGS. 6 and 7. As the suction drum 65 rotates, the external surface of the flange 78 a slides on the tight-pressed surface of the sucking blowing block 70. This configuration makes it possible to suck the photo film web 26 through some of the air holes 63 to keep it on the peripheral surface of the suction drum 65 and, simultaneously, blow the photo film web 26 through other groups of the air holes 63 to separate it from the peripheral surface of the suction drum 65, in accordance with the rotational phases of the suction drum 65.

Since all of the openings 83 move along the same track, as shown in FIG. 7, the suction hole 91 is formed to extend along the track, so as to be connected to some of the openings 83 which lead to those ones of the air holes 63 which exit in a rotational range of the suction drum 65 from a winding start point P1 to a separating point P2 of the photo film web 26. Besides, according to the present embodiment, the suction hole 91 has a width that is greater than a diameter of the openings 83. According to this configuration, the air suction is not carried out through those air holes 63 which exit in a peripheral range that is not used for sucking the photo film web 26 onto the suction drum 65, so that it is possible to achieve a high sucking pressure even while the vacuum pump 68 can suck only a small volume of air. Consequently, the photo film web 26 is prevented from slipping on the drum periphery even if the vacuum pump 68 is a low power cheap one.

It is to be noted that the suction hole 91 does not need to be so formed as to suck the air throughout the entire range from the winding start point P1 to the separating point P2. Insofar as the photo film web 26 is prevented from slipping, the suction hole 91 may have such a shape that the air is sucked merely in a limited range between these points P1 and P2, the limited range being defined according to a winding angle of the photo film web 26 around the drum periphery, i.e. a rotational angle between these points P1 and P2.

In the present embodiment, the blowing hole 92 has a larger diameter than the openings 83, and is located such that at least one of the openings 83 is connected to the blowing hole 92 when those air holes 63 which are connected to the one opening 83 come to the separating point P2. Accordingly, the air holes 63, which have been sucking the photo film web 26 to keep it on the peripheral surface of the suction drum 65, start blowing the air when they come to the separating point P2, so that the photo film web 26 is forced to separate from the drum periphery at the separating point P2. As a result, the photo film web 26 is stably held on the drum periphery, and is peeled off the drum periphery without fail, so that the photo film web 26 is conveyed properly.

Because the suction drum 65 rotates while the sucking blowing block 70 is tightly pressed onto the side surface of the suction drum 65, that is, the external surface of the flange 78 a, the external surface of the flange 78 a and the tight-pressed surface of the sucking blowing block 70 are coated with lubricant 93 (see FIG. 9) for reducing abrasion of these surfaces. As the lubricant 93, high-viscosity grease is used in the present embodiment. The lubricant 93 may be applied on these surfaces by any appropriate conventional method. For example, the sucking blowing block 70 a may have an internal lubrication pipe whose one end is exposed to the tight-pressed surface, and the other end is exposed to an appropriate surface.

If the external surface of the flange 78 a and the tight-pressed surface of the sucking blowing block 70 are not sufficiently lubricated, i.e. coated with the lubricant 93, these frictional surfaces will wear off rapidly. To prevent the wearing, it is necessary to periodically lubricate these surfaces with the lubricant 93, which adds to the labor of the operator who is in charge of maintaining the suction drum device 52. To solve this problem, according to the present invention, a plural number of recesses 94 are formed for pooling the lubricant 93 in the tight-pressed surface of the sucking blowing block 70, as shown in FIG. 6. Thereby, it becomes possible to pool the lubricant 93 in the recesses 94, so that the amount of lubrication may be increased. Furthermore, it is possible to adjust the pooling amount of the lubricant 93 by adjusting the number, shape and depth of the recesses 94.

Indeed the recesses 94 in the tight-pressed surface of the sucking blowing block 70 allow increasing the coating amount of the lubricant 93, but the lubricant 93 collects in the openings 83 because the flange 78 a and the tight-pressed surface of the sucking blowing block 70 are both flat. As a result, the lubricant 93 leaks from the opening 83 into the air duct 80 as the air is sent from the air blower 69 when the opening 83 is connected to the air blower 69 through the blowing hole 92. The leakage causes running out of the lubricant 93 in a shorter time, or the lubricant 93 leaked in the air duct 80 may be ejected out of the air holes 63 with the blowing air, and smear the photo film web 26. Moreover, since the air is always sucked through the suction hole 91, the lubricant 93 may collect in the sucking hole 91, and then leak into the sucking pipe 89.

To prevent the leakage of the lubricant 93, according to the present embodiment, endless grooves 95 and 96 are formed around the openings 83 and the suction hole 91 respectively, as shown in FIGS. 7 and 9, wherein FIGS. 8 and 9 show a front view and a sectional view of one of the openings 83, respectively. According to the present embodiment, provided that the openings 83 has a diameter F1 of 9 mm, and the blowing hole 92 has a diameter F2 of 18 mm, the endless groove 95 has an external diameter F3 of 16 mm. The suction hole 91 has almost the same profile as the blowing hole 92, so its sectional view is omitted from the drawings. For example, where the suction hole 91 has a width of 15 mm, an outline of the endless groove 96 has a width of 22 mm across the width of the suction hole 91. The above mentioned values may vary appropriately from one apparatus to another. Since the endless grooves 95 and 96 are formed to surround the openings 83 and the suction hole 91 respectively, the endless grooves 95 and 96 serve as oil sinks to accept the lubricant 93, hindering the lubricant 93 from collecting in the openings 83 and the suction hole 91.

Even with the endless grooves 95 and 96, if an end face or rim of each opening 83 is in contact with the tight-pressed surface of the sucking blowing block 70, or if an end face or rim of the suction hole 91 is in contact with the flange 78 a, the lubricant 93 may collect in the openings 83 and the suction hole 91. For this reason, according to the present embodiment, a boundary wall 97 between the opening 83 and the endless groove 95 is formed lower by a given height “h” than the surface of the flange 78 a, to recess the rim of the opening 83, as shown in FIG. 9. The height “h” is 2.5 mm in the present embodiment, but may vary appropriately. In the same way, a boundary wall 98 between the suction hole 91 and the endless groove 96 is formed lower by a given height “h” than the surface of the tight-pressed surface of the sucking blowing block 70. Thereby, the rims or end faces of the openings 83 and the suction hole 91 are kept away from the tight-pressed surface of the sucking blowing block 70 and the flange 78 a respectively, so the lubricant 93 is prevented from collecting in the openings 83 or the suction hole 91.

Furthermore, in order to prevent leakage of the lubricant 93 from the endless grooves 95 and 96 through outer peripheries of the boundary walls 97 and 98 into the openings 83 and the suction hole 91, an internal oil trapping groove 100 is formed around a base portion of the boundary wall 97, as shown in FIG. 9, and in the same way, a not shown internal groove is formed around a base portion of the boundary wall 98. It is possible to form such an internal groove around an appropriate portion of the outer peripheries of the boundary walls 97 and 98, in place of or in addition to the base portion.

As described so far, according to the presents embodiment, the endless grooves 95 and 96 are formed around the openings 83 and the suction hole 91, the rims of the boundary walls 97 and 98 are set back from the external surface of the flange 78 a and the tight-pressed surface of the sucking blowing block 70, and the oil trapping grooves 100 are formed around the outer peripheries of the boundary walls 97 and 98 to trap and prevent the lubricant 93 from flowing out of the endless grooves 95 and 96. These configurations prevent the lubricant 93 from collecting in the openings 83 and the suction hole 91 even while the lubricant 93 is sufficiently applied. Therefore, the present embodiment effectively reduce the leakage of the lubricant 93 through the openings 83 into the air duct 80, which can be caused by the air sent from the air blower 69 through the blowing pipe 90, as well as the leakage of the lubricant 93 through the suction hole 91 into the sucking pile 89, which can be caused by the air sucked by the vacuum pump 68.

Now the overall operation of the manufacturing line 10 using the above-described suction drum device 52 will be described. When the operator starts operating the line, the photo film web 26 is pulled out from one of the film rolls 27 a and 27 b that are loaded in the film supplier 22, and is conveyed through the dancer roller device 49 a or 49 b, the roll switching device 50 and the film splicer 51 to the suction drum device 52, as shown in FIG. 2.

As being conveyed to the suction drum device 52, the photo film web 26 is wound around the peripheral surface of the suction drum 65 with its photosensitive surface outside, as shown in FIGS. 2 and 7. While the air holes 63 formed through the drum peripheral surface are moved from the winding start point P1 to the separating point P2, the openings 83 leading to these air holes 63 are connected through the suction hole 91 to the vacuum pump 68, so the air is sucked through these air holes 63. Accordingly, the photo film web 26, after being wound around the drum peripheral surface, is sucked and held on the drum peripheral surface to prevent the slippage of the photo film web 26 till it comes to the separating point P1.

When the air holes 63 come to the separating point P2, the openings 83 leading to these air holes 63 are connected to the air blower 90 through the blowing hole 92, so the air is blown out through these air holes 63. As a result, the photo film web 26 is forced to separate from the drum peripheral surface at the separating point P2, to be sent toward the film cutter 23.

Since the sucking blowing block 70 is formed with the recesses 94 in its tight-pressed surface to the flange 78 a, i.e. the side surface of the suction drum 65, as shown in FIG. 6, it is possible to coat the tight-pressed surface with a sufficient amount of lubricant 93 at one time. Therefore, the suction drum device 52 would not run out of the lubricant 93 for a long time without the need for supplementing the lubricant 93 periodically. Furthermore, even with the increased amount of lubrication, the lubricant 93 is prevented from collecting in the openings 83 and the suction hole 91, because the endless grooves 95 and 96 are formed around the openings 83 and the suction hole 91, such that the boundary walls 97 and 98 between the endless grooves 95 and 96, on one hand, and the openings 83 and the suction hole 91, on the other hand, are set back from the external surface of the flange 78 a and the tight-pressed surface of the sucking blowing block 70 respectively, and that the oil trapping grooves 100 are formed around the outer peripheries of the boundary walls 97 and 98. Accordingly, it is possible to suppress the leakage of the lubricant 93 through the openings 83 into the air duct 80, which can be caused by the air sent from the air blower 69, or the leakage of the lubricant 93 into the sucking pile 89, which can be caused by the air sucked by the vacuum pump 68.

The photo film web 26 fed out from the suction drum device 52 is printed on its side margins with film data, such as film size, film speed and film type, and then fed to the film cutter 23. The film cutter 23 cuts the photo film web 26 into the predetermined length to provide the photo filmstrip 13. The photo filmstrip 13 is fed to the bonding tape applier 24, which puts the not-shown adhesive tape on the trailing end of each photo filmstrip 13. Thereafter, the photo filmstrip 13 is conveyed to the spool supply line 20.

Simultaneously, the backing paper supplier 29 withdraws the backing paper 32 from the roll a predetermined length at a time, trims the backing paper, provides the backing paper with perforations for use in winding it around the spool 19 and, thereafter, feeds it to the sealing tape applier 30. The sealing tape applier 30 puts the sealing tape on the predetermined positions of the backing paper 32. Thereafter, the backing paper 32 is fed to the backing paper cutter 31.

At the first station ST1 of the spool turret 35, the spool supplier 36 places the spool 19 in the spool holder 46. Then, the spool turret 35 turns through a predetermined angle to stop the spool holder 46, after having the spool 19 placed therein, at the second station ST2. At the second station ST2, the spool positioning machine 37 positions the not-shown slit of the spool 19. When the spool 19, after being positioned, comes to the second station ST3, a leading end of the backing paper 32 is inserted into the slit of the spool 19.

Next, a not-shown motor of the winding machine 38, which is coupled to the spool holder 46 at the third station ST3, drives the spool 19 to rotate several turns in a winding direction, to wind the backing paper 32 around the spool 19. After the backing paper 32 is wound around the spool 19 in several convolutions, the film supply line 14 supplies the photo filmstrip 13 and put it on a reverse surface of the backing paper 32. Then the motor rotates the spool 19 further in the winding direction, to wind the backing paper 32 and the photo filmstrip 13 around the spool 19. The touch roller device 47 presses the backing paper 32 and the photo filmstrip 13 onto the shaft of the spool 19 with an appropriate pressure, to push the air out of a gap between the backing paper 32 and the photo filmstrip 13. Since the back tension roller pair 34 apply an appropriate tension to the backing paper 32, the backing paper 32 is prevented from meandering, so it is wound around the spool 19 neatly. The backing paper cutter 31 cuts the backing paper 32 into the backing paper strip each time the backing paper 32 is wound up by the predetermined length onto the spool 19.

After having the photo filmstrip 13 and the backing paper 32 wound thereon at the third station ST3, the spool 19 is carried to the fourth station ST4 by the intermittent rotation of the spool turret 35, while the touch roller device 47 keeps pressing the backing paper 32 to stop it from unwinding. At the fourth station ST4, the folding machine 39 folds the trailing end of the backing paper strip 32 inward.

At the fifth station ST5, the seal wrapping machine 40 wraps the sealing tape around the rolled backing paper strip. At the sixth station ST6, the inspector 43 inspects the diameter of each of the manufactured photo film rolls 42. Those photo film rolls 42 which are judged to be defective are removed from the spool holder 46, and ejected from the inspector 43. Those photo film rolls 42 which are judged to be good are transferred from the spool holder 46 to the accumulating conveyer 44 at the seventh station ST7, to be conveyed to the packaging machine and the like.

Although the recesses 94 are formed in the tight-pressed surface of the sucking blowing block 70 in the above embodiment, such recesses may be formed in the external surface of the flange 78 a, i.e. in the side surface of the suction drum 65. The sucking blowing block 70 is formed to have a substantially cylindrical shape in the above embodiment, but the sucking blowing block 70 may have another shape insofar as it has a flat surface that is pressed tightly onto the suction drum 65, particularly the external surface of the flange 78 a. The openings 83 are round in the illustrated embodiment, but they may have any appropriate shape.

In the above embodiment, the lubricant 93 is prevented from collecting in the openings 83 and the suction hole 91 by forming the endless grooves 95 and 96 around the openings 83 and the suction hole 91, such that the boundary walls 97 and 98 are set back from the external surface of the flange 78 a and the tight-pressed surface of the sucking blowing block 70 respectively, and by forming the oil trapping grooves 100 around the outer peripheries of the boundary walls 97 and 98. But in order to suppress the leakage of the lubricant 93 to some extent, it is not always necessary to form the oil trapping grooves 100, but they may be omitted, as shown in FIG. 10. Omitting the oil trapping grooves 100 save the manufacturing cost of the suction drum 65, though a small amount of oil leakage can occur. For more reduction of the manufacturing cost of the suction drum 65, the boundary walls 97 and 98 may be flat to the external surface of the flange 78 a and the tight-pressed surface of the sucking blowing block 70 respectively, though it could result in increasing the amount of oil leakage.

Although the endless groove 96 are formed around the suction hole 91 in order to prevent leakage of the lubricant 93 into the sucking pipe 89, that can be caused by the air sucked by the vacuum pump 68, the endless groove 96 may be omitted in a case where the amount of leakage of the lubricant 93 into the sucking pile 89 is small. Thereby the manufacturing cost of the sucking blowing block 70 is reduced, though the lubricant 93 may a little leak into the sucking pile 89.

Although the blowing hole 92 is formed in the tight-pressed surface of the sucking blowing block 70 so as to blow the photo film web 26 off the peripheral surface of the suction drum 65 at the predetermined separating point P1, after the photo film web 26 is sucked and held on the peripheral surface of the suction drum 65, it is possible to separate the photo film web 26 off the peripheral surface of the suction drum 65 without using the blowing force, but only by a tension that pulls the photo film web 26 downwards of the conveying direction. In that case, the blowing hole 92 may be omitted, and thus it is unnecessary to form the endless groove 95 around each opening 83. So the manufacturing cost of the sucking blowing block 70 is still more reduced.

The suction drum device 52 is disposed as a film conveying device in the film supplier 22 in the above embodiment, such a suction drum device may be disposed as a sheet conveying device in the backing paper supplier 29, in between other devices of the film supply line 14, or in between other devices of the backing paper supply line 17. Furthermore, the suction drum device of the present invention is not only applicable to the manufacturing line 10 for the photo film rolls 42, but may be used as a suction drum device for conveying a belt of belt-like material, such as a metal foil, a paper web, or paper.

The present invention is not to be limited to the suction drum device, but may be applicable to any kind of air joint that consists of a stationary member having vent holes formed through at least one of its surfaces, and a movable member having vent holes formed through a surface that slides on the surface with the vent holes of the stationary body. The vent holes of the movable member are connected to the vent holes of the stationary member so that the air flows from the vent holes of the stationary member to the vent holes of the movable member, or vise versa. In that case, grooves for catching redundant lubricants are formed around at least some of the vent holes.

Thus, the present invention is not to be limited to the above embodiments but, on the contrary, various modifications will be possible without departing from the scope of claims appended hereto. 

1. An air joint comprising: a stationary member having vent holes formed through at least one of its surfaces; a movable member having vent holes formed through a sliding surface that slides on said surface with said vent holes of said stationary body, said vent holes of said movable member being connected to said vent holes of said stationary member so the air flows from said movable member to said stationary member or vise versa via said vent holes; and first grooves formed around at least some of said vent holes.
 2. An air joint as claimed in claim 1, wherein boundary portions between said vent holes and said first grooves are set back from said sliding surface.
 3. An air joint as claimed in claim 2, wherein at least a second groove is formed in an outer peripheral surface of said boundary portion, said second groove extending in a circumferential direction of said vent hole.
 4. An air joint as claimed in claim 1, wherein said first grooves are catching redundant lubricant.
 5. An air joint as claimed in claim 1, wherein said first grooves are formed around those vent holes which are placed on downstream sides in the flowing direction of the air.
 6. A suction drum device for conveying a belt-like material, comprising: a negative pressure source; a stationary member having a suction hole formed through a surface, said suction hole leading to said negative pressure source; a rotary drum having air holes formed through an outer peripheral surface, and openings formed through a side surface of said rotary drum, said openings leading to said air holes, said side surface sliding on said surface of said stationary member to connect said openings in turn to said suction hole as said rotary drum rotates, thereby sucking the air through some of said air holes to hold said belt-like material on said outer peripheral surface; and grooves formed around said suction hole of said stationary member and/or around at least some of said openings of said rotary drum.
 7. A suction drum device as claimed in claim 6, wherein a boundary portion between said suction hole and said groove and boundary portions between said openings and said grooves are set back from said side surface of said rotary drum.
 8. A suction drum device as claimed in claim 7, wherein at least an internal groove is formed around an outer periphery of said boundary portion, said groove extending in a circumferential direction of said suction hole or said opening.
 9. A suction drum device as claimed in claim 8, wherein said internal groove is formed around a base portion of said boundary portion.
 10. A suction drum device as claimed in claim 8, wherein said grooves and said internal groove are catching redundant lubricant.
 11. A suction drum device as claimed in claim 6, wherein said air holes are divided into groups of a constant number according to their positions on said outer peripheral surface of said rotary drum, and said openings lead each individually to one group of said air holes, and are arranged at regular intervals in a circle around a rotary center of said rotary drum.
 12. A suction drum device as claimed in claim 6, wherein said surface having said suction hole of said stationary member is tightly pressed on said side surface of said rotary drum.
 13. A suction drum device as claimed in claim 6, wherein said stationary member further has a blowing hole connected to a positive pressure source, said blowing hole being formed through said surface having said suction hole, wherein said suction hole is connected to a constant number of successive ones of said openings so as to suck the air through those groups of said air holes which lead to said successive openings, whereas said blowing hole is connected to at least one of said openings so as to blow out the air through said air holes which lead to said at least one opening.
 14. A suction drum device as claimed in claim 6, wherein said openings are arranged at the same radius from said rotary center of said rotary drum, and lead to said air holes through air ducts that are formed radially in said rotary drum.
 15. A suction drum device as claimed in claim 14, wherein each of said openings leads to one group of said air holes through one of said air ducts.
 16. A suction drum device as claimed in claim 6, wherein said stationary member is fixed in a rotational direction of said rotary drum, but is movable in an axial direction of said rotary drum. 